This Pull Request is for HacktoberFest 2020

Description of Change

Checklist

• Added description

Add quickselect algorithm. Quickselect is a selection algorithm to find the kth smallest element in an unordered list.

Description of Change

References

Checklist

Is your feature request related to a problem? Please describe.

It's not relevant for this feature request, but: this would allow CMS to trace autoparsing by setting an environment variable, after root-project/root#7609 is merged.

Describe the solution you'd like

export ROOT_LOG='ROOT.InterpreterPerf=Debug(3),ROOT.RBrowser=Error'

should set ve

IEEE 754 recommends (but does not require) a compound function, which is in the process of being standardized for C and C++; we should expose it in swift-numerics. The simplest, most literal translation of the operation into Swift would be:

extension RealFunctions {
  /// (1+x)ⁿ
  /// 
  /// Returns NaN if x < -1.
  static func compound(_ x: Self, _ n: Int) -> Self {
    // not

The igraph tutorial (here online, source file here) should be reviewed:

• Is it up to date?
• Is it understandable by a newcomer?
• Are essential points unexplained or missing?

Ideally, this should be done by someone who is new to using igraph, to get a fresh perspective. Th